As the article points out there are societal, legislative and liability hurdles to overcome. It's difficult for the car makers to predict if and when (and by what measure) they are able to jump over these hurdles. But from the technical implementation perspective there are some known hurdles. Specifically when we talk about ADAS systems taking control of the car dynamics, be it braking, steering, whatever. As the IHS contributor mentioned there are many components inside these ADAS systems: Microprocessors, FPGA's, DSP's, memories and so on. If the ADAS system is to really take control of the car, then the components used in the decision making need to be robust enough to guarantee operation over the life of the car. Similarly there needs to be built in redundancy to ensure that should a component fail, it does so in a safe way (so called graceful degradation of vehicle functionality). The functional safety standard for automotive systems is called ISO26262 and so far not too many ADAS processors are capable of being assesed against this standard. nor are they typically robust enough to guarantee operation over life for an automobile. So the component manufacturers and tier 1 integrators have some work to do in order to deliver truely fail safe systems for semi autonomous cars. I think this is the first challenge facing the industry.

It may be slightly early to start using autonomous cars but thats the future going to be. Anything that a we are highly dependant on like our phone, automobile or home its going to be very very smart in future.

junko.yoshida wrote: ... there are just so many more cities they need to "master"!

Mountain View is a decent place to start, especially at non-rush hour. But at some point they need to try out the "Bloody Bayshore" AKA US 101. We'll see if they're able to survive that one any better than the human drivers.

The future of autonomous vehicles is package delivery. Think UPS or Pizza Hut. Here's a vehicle with no passengers. Only drives local roads in predefined routes at less than 30 mph. Couple it with a drone to drop the package on your doorstep. The drone only has to carry a small weight a short distance before returning to a charging station on the vehicle. It's a totally automated delivery system.

This thread of discussions on unwritten rules actually proves the point why Google is doing driving testing one city at a time. They are now focused on driving Mountain View, Calif., but there are just so many more cities they need to "master"!